From: Michal Malý <madcatxster@devoid-pointer.net>
Date: Wed, 24 Dec 2014 01:10:19 +0000 (+0100)
Subject: Improve rounding in Split_Int_Dec_Exp_Nums to hopefully avoid weird rounding errors
X-Git-Url: https://gitweb.devoid-pointer.net/?a=commitdiff_plain;h=9caae65c123a21fb55d7de9e76d2d727d87ae636;p=Nine-Q.git

Improve rounding in Split_Int_Dec_Exp_Nums to hopefully avoid weird rounding errors
---

diff --git a/bin/nine_q_config.ini b/bin/nine_q_config.ini
index ec8a478..f5aa0ef 100644
--- a/bin/nine_q_config.ini
+++ b/bin/nine_q_config.ini
@@ -4,4 +4,3 @@ Max_Connection 1000
 Session True
 Session_Lifetime 1800.0
 Session_Cleanup_Interval 3600.0
-
diff --git a/src/formatting_helpers.adb b/src/formatting_helpers.adb
index 63a8050..8b04719 100644
--- a/src/formatting_helpers.adb
+++ b/src/formatting_helpers.adb
@@ -55,6 +55,7 @@ package body Formatting_Helpers is
     package FHEF is new Ada.Numerics.Generic_Elementary_Functions(FH_Float);
     use FHEF;
 
+    EPSILON: constant FH_Float := 10.0 ** (-(Decimals + 1));
     ExpDecimals: constant FH_Float := 10.0 ** Decimals;
     PNum: FH_Float;
     Expanded: FH_Float;
@@ -80,8 +81,22 @@ package body Formatting_Helpers is
     Log_Arg_Floored := FH_Float'Floor(Log(Base => 10.0, X => PNum));
     Expanded := 10.0 ** Log_Arg_Floored;
 
-    Integer_Part_F := FH_Float'Floor(PNum / Expanded);
-    Decimal_Part := ((PNum - (Integer_Part_F * Expanded)) / Expanded) * ExpDecimals;
+    declare
+      FPE: constant FH_Float := FH_Float'Floor((PNum / Expanded) + EPSILON);
+      F: constant FH_Float := FH_Float'Floor(PNum / Expanded);
+    begin
+      if FPE > F then
+	PNum := PNum + EPSILON;
+	Integer_Part_F := FPE;
+      else
+	Integer_Part_F := F;
+      end if;
+    end;
+    --Ada.Text_IO.Put_Line("((PNum / Expanded) - Integer_Part_F) * Expanded = " & FH_Float'Image(((PNum / Expanded) - Integer_Part_F) * Expanded));
+    Decimal_Part := ((PNum / Expanded) - Integer_Part_F) * ExpDecimals;
+    if Decimal_Part < 1.0 then
+      Decimal_Part := 0.0;
+    end if;
 
     Exponent_Part := Integer(Log_Arg_Floored);
     Integer_Part := Integer(Integer_Part_F);